Currently, the application scope of the touch screen rapidly extends from a former commercial market for the minority, such as automatic teller machines of banks and industrial control computers, to the electronic field for public consumption, such as mobile phones, Personal Digital Assistants (PDAs), Global Positioning Systems (GPSs), Portable Media Players (PMPs) (such as MP3 and MP4), and even Tablet Personal Computers (Tablet PCs). Hopefully, the touch screen, of which the touch and control operation is simple, convenient and humanized, will become an optimum interface for human-machine interaction, and thus can be rapidly popularized.
Touch screen inputting has advantageous, such as simple, convenient, humanized operation and the like, but also has disadvantageous: it is very difficult to perform precise click and location operations. For example, when inputting a text, one letter in a word is wrong, and the wrong letter is desired to be selected and amended. In this case, it is very difficult for operation, and it is easy to make a wrong selection. That is mainly because: the distance between letters is very small, and when a finger operates on the touch screen, the touching area between the finger and the touch screen is large. Moreover, when performing operations (such as click) with the finger, the finger covers the sight line of the user, so it is very difficult to perform a precise operation with the finger. Of course, the problem may be solved by using a handwriting pen, but carrying and using the handwriting pen also brings inconvenience to the user. Therefore, there is the problem that the user experience is not good when an operation is performed on the touch screen, as long as the distance between operation objects is very small.